Leigh syndrome, French Canadian type

Leigh syndrome, French Canadian type (LSFC) is an inherited disease characterized by developmental delays, low muscle tone, distinctive facial features, and severe episodes of illness that can lead to early death. It is caused by defects in a protein that affects the levels of an enzyme, called COX, which is crucial for energy production in cells. Symptoms are believed to be due to low levels of the COX enzyme, leading to abnormal energy production in the cells and (ultimately) cell death, especially in the nervous system and liver. LSFC is also known as COX deficiency, French Canadian type. View testing options